Fitting construction for tanks



-June 8, 1943.

I FITTING CONSTRUCTION FOR TANKS Filed'nec. 19,V 1941 2 sheets-sheet 1 60 50 56 72 i. i I A a2 56 29 .i4 26 gg "5a 72 v -20 g4;

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June 8, 1943.' F. J. PEPERSACK FI'MjIN coNsTRUTIoN FOR TANKS.

2 sheets-sheet 2" Filed nec. `19, 1941 ,m1, a ma atented June 8, 1.943

l'rEo NT OFFICE p 2,321,417 FITTING CONSTRUCTION Foa TANKS Francis J. Pepersack, llowson, Md., assigner to The Glenn L. Martin Company, Middle River, Md., a corporation ol Maryland This invention relates to a fitting construction for tanks and particularly forj tanks adapted to contain liquid fuel and comprising a cell within a rigid housing structure. Such tanks nd appllcationas fuel and oil tanks for airplanes and are adapted to be fitted into the different parts of an aircraft fuselage or wing so that the normal structure provides the rigid confining element of the tank. For an example of this practice, reference may be had to Gray et al. Patent No. 2,102,590 disclosing a cellular form of tank applied to aircraft construction.

Of course the cellular form of tank in question is readily adaptable to other kinds of transport vehicles and especially to ships.

Itis intended primarily to provide an improved tting for access to the cell part of the tank and which will be so constructed as to produce a leakproof connection and aior d support for the cell part of the tank which is too flexible to be selfsustainingl It is a further object of the fitting of this inf vention to provide reinforcing for the cut opening in the rigid structure or cell housing. This means for reinforcing is also constructed and arranged to assist in aligning the corresponding opening in the cell element.

Since for their bullet-proof and generally impervious qualities the enclosed cell elements of such tanks are usually composed of rubber-like material, it is essential to prevent the deleterious results of cold flow which would ordinarily take place when the cell material around an opening is subjected to continuous and heavy clamping pressure bya fitting.k To meet this aspect of the problem, rigid means have been provided for protecting the rubber-like material defining the cell opening from the clamping pressure, and sealing layers havebeen added to give the required uid tightness.

One of the advantages of the novel construction which will be pointed out in detail resides in the provision of a single detachable means for establishing the required clamping relation of the rigid fitting, the rigid structure, and the cell element.

A special object of the invention is to provide a tank tting construction of the typegenerally described in which a single fitting is formed to provide a fluid conduit between two such tanks and a leak-proof connection with the opening of each.

Other features of novelty contributing to the effectiveness and simplicity ofthe tank construction of this invention will be pointed out in connecuon with the f ouwing detaued description of several embodiments taken in connection with the accompanying drawings, in which Fig. 1 shows, in vertical section, one form of In Fig. 1, a highly flexible or pliant cell III of rubber-like material is housed in a. rigid frame The cell I0 is of the self-sealing variety and includes an inner layer It, an interstructure I2.

' mediate sealant layer IS, and an outer layer I8,

comprising a three-ply lamination subject to cold flow under pressure. In particular, the inner layer Id will preferably be of a synthetic rubber known commercially as Neoprene, because of its resistance to attack by liquid hydrocarbon fuels. Crude unvulcanized rubber is used for the intermediate layer l 6 in order to provide a sealing action and prevent leakage following bullet penetration. The outer layer I 8 which contacts the housing structure I2 is by preference formed of soft vulcanized rubber. It is to be further noted that an inner reinforcing layer or lining I9 covers the liquid side of the cell and that this member may be of fabric impregnated with Neoprene. These three layers and the inner reinforcing lining I9 are adhesively bonded after suitable surface treatment to improve the grip of the adhesive. This bullet-proof cell construction comprises the subject-matter of Gray and DeWeese patent application Serial No. 338,052, filed May 31, 1940, entitled Self-sealing tank.

An opening 20 is shown extending uniformly through the metallic frame structure I2 and the three rubber-like layers of the cell I0. A rigid ring or tubing 22 is closely fitted within the portion of the opening 20 defined by cell layers It, I6 and I 8 and has the total thickness of these layers in unstressed condition. The ring 22 is preferably formed from a phenolic condensatematerial such as Bakelite, or from molded fibre, and has important functions which will be described subsequently. Particular note is made of the` fact that the reinforcing fabric layer I9 extends inwardly of the opening 20 and covers the lower facepof the molded ring 22. lInllike manner, an inner reinforcing member 24 of washer shape and comprising a heavy fabric impregnated with Neoprene surrounds the opening 20 and overlaps it to cover the inner face of the rigid ring 22. A fabric seam cover 26 of balloon cloth treated with neoprene entirely covers the inner reinforcing member 24. Both the reinforcing member 24 and its seam cover 26 are adhe neoprene. A hand hole is provided in the.

cell to give convenient access.

sively secured in place'by a suitable cement. The

seal of the non-resilient ring 22 within the wall opening of cell I is completed by an outer, heavy fabric reinforcing member 28 of circular shape extending over the uppermost face of ring 22, 'and adhesively attached to it and the adjacent flush surface o'f cell I0. Reinforcing member 28 is similar to member 24.

On the outer side of the stiff confining structure I2 a generally tubular adapter 29 comprising an outwardly extending, shouldered flange 30 and an integral sleeve 32-is fitted within the opening 20 and secured to the outer side of structure I2 by means such as rivets 34. The ange 30 reinforces the structure I2 around its opening 20 and provides a bearing abutment -for the ring 22 and its sealing cover members. Itw'ill be observed that the integral sleeve 32 of the anged its lateral ange portion 30. y

An opposed pairrof rigid outer and inner adapterA 29 extends continuously above and below i clamping members 36 and 38, respectively, are

lso formed as to provide a continuous-passageway with the intermediate sleeve 32. These clamping members may take a variety of forms. -As illustrated in Fig. 1, the outer clamping member 36 is represented as an elbow or L, and the inner clamping member 38 is of spider form. A single, detachablev clamping means in the form of a bolt 40 extends through the adapter sleeve 32 and engages the two clamping members 36 and 38. 'I'he outer clamping member 36 is formed with a circular flange 42 having a spaced pair of ridges 44 on its. inner face for engaging a suitable sealing gasket 46 resting upon the outer side of the shouldered ange 30. The clamping member flange 42 is of approximately the same width as'the adjacent face of rigid ring 22 and snugly engages the outer Wall of the sleeve 32.

The elbow tting or clamping member 36 has a large passage 48 and a smaller passage including a threadedly attached elbow 50.

The inner. clamping member 38 is formed to provide a circular clamping face 52 sliding over the inner end of adapter sleeve 32 and having a pair of spaced ridges 54 engages the portion of the seam cover 26 and outer reinforcing member 28 covering the underside of the rigid ring member 22. served that the `inner face of ange which is flush with the corresponding face of the rigid metal structure I2, has a similar and opposed pair of spaced ridges 56 which clamp against the outer reinforcing member 28. In staggered re- In this connection, it will be oblation to these opposed pairs of ridges, the intering a countersunk, liquid sealing washer 14 of 75 In assembling the tank and tting of the Fig. l embodiment, the adapter 29 will 'be secured to structure I2 so that the inwardly extending end of its sleeve 32 will serve as a pilot guide for the cell opening defined by thel rigid ring 22. It remains then only to place. the exterior gasket 46 and the outer clamping member 36 over the upper end of sleeve 32, slide the inside spider-like clamping member 36 over sleeve 32, and tighten the stop nut 10 on the outer end of the bolt 40. Suitable peripheral sealing will be accomplished by the clamping of rubber impregnated inner and outer reinforcing members 24 and 28 against the noncompressible ring 22, Ithus leaving the three adjacent rubber-like layers I4, I6 and I8 comprising the body of the cell free from compression.

In the easily and quickly linstalled construction which has been described, the non-resilient` ring 22 prevents cold iiow of the clamped flexible cll material and provides a rigid opening in the wall of the otherwise highly flexible cell. It is also particularly noteworthy that the shouldered flange 30 of the adapter ring acts as a reinforcing member for the cut open in the cell housing or airplane structure I2, thus avoiding sealing of this structure plus a reinforcing; and that the projecting sleeve 32 serves as a guide for the installation of the cell I0 and has a bearing for rigid ring 22 to prevent shifting of the cell. The adapter sleeve 32 likewise serves as a contact surface for the outer clamping member or tting 36.

Assembly is greatly facilitated by having only a single clamping bolt with an outwardly exposed nut to press all of the members into their required relation.

The embodiment of the invention illustrated by the. hull tank outlet and ller of Fig. 2 closely resembles that which has been described in detail with reference to Fig. 1. The construction of the cell |50 and rigid housing structure I2 are the same, but it will be noted that' the outer and 88 and countersunk neoprene sealing washer 14.

The inner end of the bolt has an elastic stop nut secured by a somewhat modified form of nut clip 92 tted on face 84 in non-turning relation.

A non-resilient, Bakelite or bre, ring 94, practically identical with the same element in Fig. 1, has a pair of ridges 95, 95, on its inner face and an intermediate ridge 96 on its outer face, for engaging respectively the inner and outer cell opening reinforcing members.

The outer clamping member 'I6 is formed with a circular flange 98 having a single clamping ridge |00 bearing against the gasket 46. In this embodiment, the tubular adapter has its shouldered flange |06 secured to the inner surface of the rigid housing structure I2 by means such as rivets |08 and has an integral, opening-deining sleeve |I0 similar to that 'previously described. If desired, the outer face of ange |06 may also be provided .with a spaced pair of ridges for gripping thel gasket 46. The assembly and the use of this outlet and iill'er tting for a self-sealing cell 'will be apparent from the description of the embodiment of Fig. 1.

Fig. 3 illustrates the application of the principles of this invention to a ventfor a wing tank and its adaptation to a dierent cell construction not requiring the rigid ring of the two previous embodiments.

A rigid structure I2 houses a pliant cell ||2 composed of a relatively thin wall layer ||4 of synthetic rubber or neoprene and reinforced about the vent opening byan inner reinforcement layer ||6 Vresembling a large washer and preferably formed from a heavy fabric impregnated with neoprene. struction, this reinforcement member |.|6 has its seam covered and inner surface sealed by a layer IIB preferably of balloon cloth fabric impregnated Vwith neoprene and ladhesively attached. Where neoprene is mentioned as one of the materials comprising the cell, it is to be understood that other suitable pliable substances which are resistant to the action of hydrocarbons may be used. An outer reinforcing member |20 similar in all respects to the inner member ||6 but of somewhat larger outside diameter is adhesively secured to the cell wall II4 and completes the reinforcement of its opening.

Similar reference numerals have been used for parts identical with those previously described in detail. Thus, the tubular adapter having housing reinforcing ange |06 and sleeve ||0 is the same as for the embodiment of Fig. 2. Ink

this particular fitting, the upper clamping member |22 comprises an L and thelower lclamping member |24 is of the previously used spider form. The upper clamping member |22 has a transverse flange |26 with a ridge |28 on the face where it engages gasket 46. The spider-like lower clamping member |24 is provided with a circular ange |30 with a single ridge |32 on the face abutting the similar cover layer H6. In common with all illustrated forms of the invention, a single bolt |34 is used to maintain the required clamping relation. This bolt has an outer head |36 engaging a washer |38 overlying a countersunk neoprene sealed washer |40. A stop nut on the inside end of the bolt |36 is held against turning by a clip |64 tted on the innermost end of the clamping member |24.

While this embodiment is independent of the rigid ring for preventing compression of the cell material, attention is .called to the fact that it possesses all of the advantages and utility which the combined ange and. sleeve adapter and single separable clamping means aiord. y

A further useful form of the present invention is illustrated in Fig. 4 as an interconnector for an adjacent pair of tank cells. In this instance, a pair of tanks are arranged to have the approximately parallel, spaced portions indicated bythe drawings, and each comprises a cell l and coniining, rigid structure |2, as described in detail for Fig. 1. The aligned pair of openings for each tank are also in alignment with each other. A particular feature of this embodiment is a double-ended adapter |48 spacing and providing communication between the interiors of the adjacent tanks.

An integraly shouldered ange |50 at the left end of this sleeve adapter has an outer portion |52 underlying the housing structure I2 and secured thereto by bolt means |54. The shouldered iiange |50 includes also an inwardly pro.

As in the other cell conof the tubular adapted |48 hagan opposed pair of ear portions for receiving the small attaching bolt means |62 and reinforcing the outer surface of the underlying housing structure I2 around its opening. An inwardly faced ridged clamping flange |64 engages the outer surface of the clamped portion of the other cell I0.

A spider form of clamping member |66 within the left end cell I0 cooperates with the clamping iiange |56. At the right end an identical clamping member |68 is disposed in cooperative relation with the clamping ange |64 and the intervening portion of cell' I0. Along bolt |10 extends centrally through the adapter |48 and through the inner clamping members |66 and |68'so as to draw the assembly ing relation.

A ridgedclamping flange |12 on the member |66 and an identical clamping iiange |14 on the opposite member |68 are of such internal diameter as to t over short inward sleeve extensions |18 and |80 at the respective ends of the adapter |48. These extensions |18 and |80 may be slotted las shown to clear the clamping members when used with athinner cell. To ground the bolt |10 and its metallic clamping parts, a bonding jumper |16 interconnects the bolt with the adjacent inward ring extension |80.

The use of a common double-ended, tubular adapter |48 between two tanks permits the eliminatlon of two separate clamping members for the outer side of these tanks and the securing of two apertured cell portions in supporting relationto their housing structures by means of a single bolt or the like.

Those versed in this art will appreciate that the non-resilient ring in combination' with the opening of a tank cell and the reinforcing members for sealing the ring around the opening will have utility in other relations where it is necessary and desirable to prevent cold ow deformation of the rubber-like material adjacent the opening.

The term rlng" as used in the specification and the appended claims is intended to 'meantA any form 'of continuous or annulus member, be

it round, rectangular or other shape, as dictated by the dimensions of the space available'and the nature of the itting to be used for the clamping. Likewise, it will be observed that the principlesof this invention disclosed herein are applicable to a cell and housing structure opening receiving other forms of ttings, for example, a valve, merely an attaching device for supporting the cell in the structure, or an access door which maybe completely removed to gain entrance to the inside of the cell.

It will be clear from the embodiments of. the invention which have been presented that nu- -merous changes may be made in the details of construction and arrangements ofthe tank and fitting parts without departing from the spirit of the invention and the scope of the appended claims.

Having thus described the invention, what is new and desired .to be secured by Letters Patent rubber-like material subject to-cold :flow and having an opening through the wall thereof, a ring of rigid material having approximately the jecting and ridged clamping face |56 bearingv unstressed thickness of the cell material subject to cold flow and closely fitted within the opening therethrough; flexible reinforcement layers secured to the inner and outer sides of the cell and overlapping the corresponding faces of the ring; and rigid means arranged in clamping relation to opposite sides of the cell wall about its opening and effective only within the face areas of the ring.

2. In combination with a liquid fuel or lubricant tank cell comprising one or more layers of rubber-like material subject to cold flow and having an opening through the wall thereof, a non-resilient annulus member having approximately the unstressed thickness of the cell material subject to cold ow and closely tted within the opening therethrough; flexible reinforcement layers secured to the inner and outer sides of the cell and overlapping the corresponding` faces of the annulus member; and passaged means arranged in clamping relation to opposite -sides of the cell wall and effective only within the face areas of the annulus member.

3. In combination with a liquid fuel or lubricant tank cell comprising one or more layers of rubber-like material subject to cold ow and having an opening through the wall thereof, a relatively undeformable ring having approximately the unstressed thickness of the cell material subject to cold ow and closely fitted within theV cell opening; exible means secured to the inner and outer sides of the cell and overlapping the corresponding faces of the ring for sealing the juncture between the tank cell and the ring; and means arranged in clamping relation to opposite sides of the cell wall and effective within the face areas of the ring.

4. The combination with a spaced pair-of flexible rubber-like cells each provided with .an opening in its wall and coniined by a rigid structure formed with an opening concentric with the cell opening, the openings lof both cells being aligned, of a continuous tubular adapter extending between vvthe two cells and structures having at Ieach -end an outwardly extending flange joined to a sleeve portion extending inwardly through the openings in said cells and said rigid structures', said adapter flanges each being secured to one of the rigid structures about its opening; a passaged clamping member within each cell encircling the corresponding end of the adapter sleeve, said .adapter flanges and clamping members being constructed and arranged to receive the marginal portion of the cell wall adjacentits opening therebetween; and separable means for imposing clamping pressure on said marginal portions of the cell walls through the adapter flanges and the clamping members. v

5. As a subcombination, a liquid fuel or lubricant tank including a. highly flexible container cell comprising one or more layers of material subject to cold flow under compression, said container cell being provided with an opening through its wall; a non-resilient ring having approximately the total thickness of said cell material in uncompressed condition fitted within the opening of said cell; and sealing layers adhesively securedto the inner and outer sides of the container cell about its opening and formed and arranged to cover the abutment lines b'e.

tween said ring and said cell.V

6. As a suboombination, a liquid fuel or lubricant tank including a highly flexible container cell comprising one or more layers of material subject to cold flow under compression, said container cell being provided with an opening through its Wall; a non-resilient ring having approximately the total thickness of said cell material in uncompressed condition tted within the opening of said cell; sealing layers adhesively secured to the inner and outer sides of the container cell about its opening and formed' and arranged to cover theV abutment lines between said ring and said cell; and means for clamping the portion of the container cell adjacent said ring to a rigid confining structure, said clamp- 'ing means being Vadapted to act only on said ring so as not to compress the wall of the container cell.

'7. Means for attaching a flexible cell of rub- -ber-like material to a rigid confining structure .and defining a continuous opening through the wall of 'said cell and said structure, comprising a tubular adapter having a sleeve portion for extending through and aligning the openings of said cell and said confining structure, said adapter having also 'a ange intermediate its.

length formed and arranged to be secured around the opening of said confining structure; and an opposed pair' of passaged clamping members for acting upon the ange of the adapter ring and the cell material around its opening to attach the cell to the confining structure and peripherally seal both sides of the cell wall at its opening.

FRANCIS J. PEPERSACK. 

